There is a large firey ball in the sky called the sun. Tesla captures its energy using a technology called solar panels.

You call it middleman, I call it platform. Owning the platform everyone uses for charging their car is not a bad place to be. Add to this that they're working on including house solar+batteries into a national smart grid system, and they're producing their own large scale energy storage and generation technology... they're positioning themselves to be a major player in the energy industry.